Scholarly Works (129 results)

This report examines recent experiences in the U.S. with transit-supportive developments – projects which, by design, give attention to the particular needs of transit users and pedestrians. The study focuses mainly on experiences in the suburbs and exurbs of large U.S. metropolises, which in most cases are served only by bus transit. Assessments are carried out at three levels – individual sites, neighborhoods, and communities. Since in the course of the research we found fewer U.S. examples of transit-supportive developments in bus-only suburban-exurban environs than popular accounts might have us believe, the study gives particular emphasis to implementation issues – how recent market and regulatory factors have influenced the transit-supportive design movement.

Living in suburbia, owning a house, and watching the kids play on a green lawn was the American dream as early as the 1800s. At first, mass transit was crucial to suburban life, with streetcars and rail lines providing access to new residential areas outside of cities. After World War II, as automobiles became even more popular and the pace of suburbanization accelerated, the American dream expanded to include two cars in every garage. For the mass transportation industry, this spelled disaster.

Chinese cities and other rapidly urbanizing parts of the developing world face immense challenges as they attempt to balance and jointly pursue economic development and environmental sustainability objectives. Chinese cities like Beijing, Shanghai, and Dalian are experiencing motorization rates of 20% to 25% annually.1 The sheer scale and rapidity of growth in the population of automobiles is daunting, challenging and at times overwhelming the institutional and administrative capacities of local and national agencies to build sufficient infrastructure and strategically plan for and manage travel demand.

Over the past decade, many Chinese cities have adopted a traditional western approach in responding to mounting problems of traffic congestion, airborne pollutants, rising accident rates, and other ills associated with automobile-oriented societies. This has been one of mainly technological and supply-side solutions, in the form of super-freeways and viaducts, expansive roadway capacity, intelligent transportation systems (ITS), and other technical exigencies that seek to accommodate pressures wrought by rapid motorization.

Might this be placing Chinese cities on the same trajectory followed by most American cities and increasing numbers of those in Europe, Canada, and Australasia: rising automobile dependency and the associated problems of galloping sprawl, fossil-fuel resource depletion, high rates of greenhouse gas emissions, and social exclusion by class and ethnicity?

SUBURBAN traffic congestion has emerged as one of the most pressing problems in the transportation field today and, most probably, will hold center stage in the transportation policy arena for years to come. Most accounts link the suburbanization of congestion to the suburbanization of jobs during the 1980s.1 Indeed, recent surges in suburban office employment have fundamentally altered commuting patterns, giving rise to,far more cross-town, reverse-direction, and lateral travel movements than in years past. This dispersal of jobs and commuting has been a mixed blessing of sorts. While on theone hand it has relieved some downtowns of additional traffic and brought jobs closer to some suburbanites, on the other hand it has flooded many outlying thoroughfares with unprecedented volumes of traffic and seriously threatened the very quality of living that lured millions of Americans to the suburbs in the first place.

Cities have always been the loci of economic productivity and social advancement. There is nothing on the horizon that would suggest this situation will change any time soon. Telecommunications advances and economic globalization will doubtlessly alter the spatial arrangement of cities in profound ways, however the inherent advantages of agglomeration (e.g., creativity spawned by face-to-face interactions, access to specialized skills, infrastructure economics) guarantee a prominent role for cities in the global economy for years to come.

Four-step travel demand forecasting models were never meant to estimate the travel impacts of neighborhood-level smart growth initiatives like transit villages, but rather to guide regional highway and transit investments. While progress has been made in enhancing large-scale models, some analysts have turned to post-processing and direct models to reduce modeling time and cost, and to better capture the travel impacts of neighborhood-scale land use strategies. This paper presents examples of direct or off-line modeling of rail and transit-oriented land use proposals for great Charlotte, the San Francisco Bay Area exurbs, and south St. Louis County. These alternative approaches provided a useful platform for scenario testing, and their results revealed that concentrating development near rail stations produced an appreciable ridership bonus. These alternative models are appropriate as sketch-planning supplements to, not substitutes for, traditional four-step models.

This paper argues that the low-density, single-use character of most suburban workplaces in the U.S. has contributed to worsening traffic congestion by making most workers highly dependent on their own automobiles for accessing jobs. To test this proposition, land use and transportation data are examined for fifty of the largest suburban employment centers in the nation. Differences in the share of trips made by various modes, commuting speeds, and levels of service on major thorough-fares connecting suburban centers are compared among clusters of centers. The densities, sizes, and land use mixtures of suburban workplaces are generally found to be important determinants of worker travel behavior and local traffic conditions.

Transit oriented development is shown to produce an appreciable ridership bonus in California. This is partly due to residential self-selection – i.e., a life-style preference for transit-oriented living – as well as factors like employer-based policies that reduce free parking and automobile subsidies. Half-mile catchments of station areas appear to be indifference zones in the sense that residents generally ride transit regardless of local urban design attributes. Out-of-neighborhood attributes, like job accessibility and street connectivity at the destination, on the other hand, have a significant bearing on transit usage among station-area residents. The presence of self-selection, shown using nested logit modeling, underscores the importance of removing barriers to residential mobility so that households are able to sort themselves, via the marketplace, to locations wellserved by transit. Market-responsive zoning, flexible residential parking policies, location efficient mortgages, and adaptive re-use of parking lots are also promising tools for expanding the supply of transit-based housing.